<header ui-dragdrop:desktop>
    <h2>
        水平向下向左树
    </h2>
    <div class="src-url">
        查看源码：
        <a ui-bind:href="srcUrl" ui-bind="srcUrl" target="_blank"></a>
    </div>
    <div class="win-btns">
        <button class="close" ui-on:click.stop="$closeDialog">关闭</button>
    </div>
</header>
<div class="content css-tree-topleft">
    <ul>
        <li>
            <span>OS</span>
            <ul>
                <li>
                    <span>NOS</span>
                    <ul>
                        <li>
                            <span>BSD</span>
                        </li>
                        <li>
                            <span>Unix</span>
                        </li>
                    </ul>
                </li>
                <li>
                    <span>DOS</span>
                    <ul>
                        <li>
                            <span>Unix</span>
                            <ul>
                                <li>
                                    <span>Mac OS X</span>
                                </li>
                            </ul>
                        </li>
                        <li>
                            <span>Windows</span>
                        </li>
                        <li>
                            <span>Linux</span>
                            <ul>
                                <li>
                                    <span>openSUSE</span>
                                </li>
                                <li>
                                    <span>Centos</span>
                                </li>
                                <li>
                                    <span>Ubuntu</span>
                                </li>
                            </ul>
                        </li>
                    </ul>
                </li>
                <li>
                    <span>SOS</span>
                </li>
            </ul>
        </li>
    </ul>
</div>